int cube_sum(int num)
{
    int res = 0, t;

    while (num) {
        t = num % 10;
        res += t * t * t;
        num /=10;
    }

    return res;
}


int fib(int n)
{
    if (n < 3)
        return 1;

    return fib(n - 1) + fib(n - 2);
}



